Question

我一直致力于通过

教程获取邮件应用程序

http://www.jondev.net/articles/Sending_Emails_without_User_Intervention_%28no_Intents%29_in_Android

但是每次尝试运行时都会出现运行时错误。我是android编程的新手，我不太清楚如何阅读logcat错误，所以我将自己置于互联网的左右，请帮忙。

我已正确设置了Internet权限，并且项目中包含了activation.jar，mail.jar和additional.jar，并为其设置了构建路径。

主要代码

 package com.dummies.android.MailTest;

 import android.app.Activity;
 import android.os.Bundle;
 import android.util.Log;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.widget.Button;
 import android.widget.Toast;

 public class MailTestActivity extends Activity 
 {
private Button mButton;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) 
   {
    mButton = (Button) findViewById(R.id.send);

    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);


    Button mButton = (Button) findViewById(R.id.send); 
    mButton.setOnClickListener(new View.OnClickListener() 
    { 
      public void onClick(View view) 
      { 
        Mail m = new Mail("********.com", "********"); 

        String[] toArr = {"*******@gmail.com"}; 
        m.setTo(toArr); 
        m.setFrom("*********.com"); 
        m.setSubject("This is an email sent using my Mail JavaMail wrapper from an        Android device."); 
        m.setBody("Email body."); 

        try { 
          //m.addAttachment("/sdcard/filelocation"); 

          if(m.send()) { 
            Toast.makeText(MailTestActivity.this, "Email was sent successfully.", Toast.LENGTH_LONG).show(); 
          } else { 
            Toast.makeText(MailTestActivity.this, "Email was not sent.",   Toast.LENGTH_LONG).show(); 
          } 
        } catch(Exception e) { 
          //Toast.makeText(MailApp.this, "There was a problem sending the email.", Toast.LENGTH_LONG).show(); 
          Log.e("MailApp", "Could not send email", e); 
        } 
      } 
    }); 
  } 
}

邮件类

 package com.dummies.android.MailTest;

 import java.util.Date; 
 import java.util.Properties; 
 import javax.activation.CommandMap; 
 import javax.activation.DataHandler; 
 import javax.activation.DataSource;  
 import javax.activation.FileDataSource; 
 import javax.activation.MailcapCommandMap; 
 import javax.mail.BodyPart; 
 import javax.mail.Multipart; 
 import javax.mail.PasswordAuthentication; 
 import javax.mail.Session; 
 import javax.mail.Transport; 
 import javax.mail.internet.InternetAddress; 
 import javax.mail.internet.MimeBodyPart; 
 import javax.mail.internet.MimeMessage; 
 import javax.mail.internet.MimeMultipart; 


 public class Mail extends javax.mail.Authenticator { 
 private String _user; 
 private String _pass; 

 private String[] _to; 
 private String _from; 

 private String _port; 
 private String _sport; 

 private String _host; 

 private String _subject; 
 private String _body; 

 private boolean _auth; 

 private boolean _debuggable; 

 private Multipart _multipart; 


 public Mail() { 
  _host = "smtp.gmail.com"; // default smtp server 
  _port = "465"; // default smtp port 
  _sport = "465"; // default socketfactory port 

  _user = ""; // username 
  _pass = ""; // password 
  _from = ""; // email sent from 
  _subject = ""; // email subject 
  _body = ""; // email body 

  _debuggable = false; // debug mode on or off - default off 
  _auth = true; // smtp authentication - default on 

  _multipart = new MimeMultipart(); 

   // There is something wrong with MailCap, javamail can not find a handler for the    multipart/mixed part, so this bit needs to be added. 
   MailcapCommandMap mc = (MailcapCommandMap) CommandMap.getDefaultCommandMap(); 
   mc.addMailcap("text/html;; x-java-content-handler=com.sun.mail.handlers.text_html"); 
   mc.addMailcap("text/xml;; x-java-content-handler=com.sun.mail.handlers.text_xml"); 
   mc.addMailcap("text/plain;; x-java-content- handler=com.sun.mail.handlers.text_plain"); 
   mc.addMailcap("multipart/*;; x-java-content-handler=com.sun.mail.handlers.multipart_mixed"); 
   mc.addMailcap("message/rfc822;; x-java-content-handler=com.sun.mail.handlers.message_rfc822"); 
   CommandMap.setDefaultCommandMap(mc); 
   } 

  public Mail(String user, String pass) { 
  this(); 

  _user = user; 
  _pass = pass; 
 } 

 public Mail(EditText user, EditText pass) 
 {
  _userE = user; 
  _passE = pass;
 }

 public boolean send() throws Exception { 
 Properties props = _setProperties(); 

 if(!_user.equals("") && !_pass.equals("") && _to.length > 0 && !_from.equals("") && !_subject.equals("") && !_body.equals("")) { 
  Session session = Session.getInstance(props, this); 

  MimeMessage msg = new MimeMessage(session); 

  msg.setFrom(new InternetAddress(_from)); 

  InternetAddress[] addressTo = new InternetAddress[_to.length]; 
  for (int i = 0; i < _to.length; i++) { 
    addressTo[i] = new InternetAddress(_to[i]); 
  } 
    msg.setRecipients(MimeMessage.RecipientType.TO, addressTo); 

  msg.setSubject(_subject); 
  msg.setSentDate(new Date()); 

  // setup message body 
  BodyPart messageBodyPart = new MimeBodyPart(); 
  messageBodyPart.setText(_body); 
  _multipart.addBodyPart(messageBodyPart); 

  // Put parts in message 
  msg.setContent(_multipart); 

  // send email 
  Transport.send(msg); 

  return true; 
  } else { 
   return false; 
  }  
  } 

 public void addAttachment(String filename) throws Exception { 
  BodyPart messageBodyPart = new MimeBodyPart(); 
 DataSource source = new FileDataSource(filename); 
 messageBodyPart.setDataHandler(new DataHandler(source)); 
 messageBodyPart.setFileName(filename); 

 _multipart.addBodyPart(messageBodyPart); 
 } 

 @Override 
 public PasswordAuthentication getPasswordAuthentication() { 
 return new PasswordAuthentication(_user, _pass); 
 } 

private Properties _setProperties() { 
Properties props = new Properties(); 

props.put("mail.smtp.host", _host); 

if(_debuggable) { 
  props.put("mail.debug", "true"); 
} 

if(_auth) { 
  props.put("mail.smtp.auth", "true"); 
} 

props.put("mail.smtp.port", _port); 
props.put("mail.smtp.socketFactory.port", _sport); 
props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory"); 
props.put("mail.smtp.socketFactory.fallback", "false"); 

return props; 
 } 

 // the getters and setters 
 public String getBody() { 
 return _body; 
 } 

 public void setBody(String _body) { 
  this._body = _body; 
 } 

 public void setSubject(String _subject) 
 { 
    this._subject = _subject; 
 }

 public void setFrom(String _from) 
 { 
    this._from = _from; 
 }

 public void setTo(String[] _to) 
 { 
    this._to = _to; 
 }

 // more of the getters and setters ….. 
 }

最后这是我的logcat

06-21 12:42:32.049: E/dalvikvm(1079): Unable to open stack trace file '/data/anr/traces.txt': Permission denied
06-21 12:42:32.859: E/dalvikvm(1079): Could not find class 'com.dummies.android.MailTest.Mail', referenced from method com.dummies.android.MailTest.MailTestActivity$1.onClick
06-21 12:42:36.820: E/AndroidRuntime(1079): FATAL EXCEPTION: main
06-21 12:42:36.820: E/AndroidRuntime(1079): java.lang.NoClassDefFoundError: com.dummies.android.MailTest.Mail
06-21 12:42:36.820: E/AndroidRuntime(1079):     at com.dummies.android.MailTest.MailTestActivity$1.onClick(MailTestActivity.java:30)
06-21 12:42:36.820: E/AndroidRuntime(1079):     at android.view.View.performClick(View.java:3511)
06-21 12:42:36.820: E/AndroidRuntime(1079):     at android.view.View$PerformClick.run(View.java:14105)
06-21 12:42:36.820: E/AndroidRuntime(1079):     at android.os.Handler.handleCallback(Handler.java:605)
06-21 12:42:36.820: E/AndroidRuntime(1079):     at android.os.Handler.dispatchMessage(Handler.java:92)
06-21 12:42:36.820: E/AndroidRuntime(1079):     at android.os.Looper.loop(Looper.java:137)
06-21 12:42:36.820: E/AndroidRuntime(1079):     at android.app.ActivityThread.main(ActivityThread.java:4424)
06-21 12:42:36.820: E/AndroidRuntime(1079):     at java.lang.reflect.Method.invokeNative(Native Method)
06-21 12:42:36.820: E/AndroidRuntime(1079):     at java.lang.reflect.Method.invoke(Method.java:511)
06-21 12:42:36.820: E/AndroidRuntime(1079):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
06-21 12:42:36.820: E/AndroidRuntime(1079):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
06-21 12:42:36.820: E/AndroidRuntime(1079):     at dalvik.system.NativeStart.main(Native Method)

编辑：由于没有对我的代码进行编辑，我没有得到NoClassDefFoundError。这两个类都直接添加到包下的src文件夹中，两个代码都没有外部添加。那我为什么现在得到这个错误呢？

Answer 1

06-21 12：42：32.859：E / dalvikvm（1079）：找不到类 ' com.dummies.android.MailTest.Mail '，引自方法 com.dummies.android.MailTest.MailTestActivity $ 1.onClick

这个错误应该是不言自明的。确保所有课程都在正确的地方。

Answer 2

Android SDK可能有错误，我在SDK包18中遇到同样的错误，所以我回到SDK包16，它对我有用。

Answer 3

答案结果比我想象的更简单，我开始的教程是较旧的。我只需要将lib文件夹的名称更改为libs，它就能完美运行！

为什么我的邮件应用程序不起作用（运行时错误）？

3 个答案: